Package org.restheart.mongodb.handlers.aggregation

Class MapReduce

java.lang.Object

org.restheart.mongodb.handlers.aggregation.AbstractAggregationOperation

org.restheart.mongodb.handlers.aggregation.MapReduce

public class MapReduce
extends AbstractAggregationOperation

represents a map reduce.

Author:

Andrea Di Cesare <andrea@softinstigate.com>

Nested Class Summary

Nested classes/interfaces inherited from class org.restheart.mongodb.handlers.aggregation.AbstractAggregationOperation

AbstractAggregationOperation.TYPE

Field Summary

Fields

Modifier and Type	Field	Description
static String	MAP_ELEMENT_NAME
static String	QUERY_ELEMENT_NAME
static String	REDUCE_ELEMENT_NAME

Fields inherited from class org.restheart.mongodb.handlers.aggregation.AbstractAggregationOperation

AGGREGATIONS_ELEMENT_NAME, TYPE_ELEMENT_NAME, URI_ELEMENT_NAME

Constructor Summary

Constructors

Constructor	Description
MapReduce(org.bson.BsonDocument properties)

Method Summary

Modifier and Type	Method	Description
String	getMap()
org.bson.BsonValue	getQuery()
String	getReduce()
String	getResolvedMap(org.bson.BsonDocument aVars)
org.bson.BsonDocument	getResolvedQuery(org.bson.BsonDocument aVars)
String	getResolvedReduce(org.bson.BsonDocument aVars)

Methods inherited from class org.restheart.mongodb.handlers.aggregation.AbstractAggregationOperation

bindAggregationVariables, checkAggregationVariables, getFromJson, getType, getUri

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAP_ELEMENT_NAME

public static final String MAP_ELEMENT_NAME

See Also:

Constant Field Values

REDUCE_ELEMENT_NAME

public static final String REDUCE_ELEMENT_NAME

See Also:

Constant Field Values

QUERY_ELEMENT_NAME

public static final String QUERY_ELEMENT_NAME

See Also:

Constant Field Values

Constructor Detail

MapReduce

public MapReduce(org.bson.BsonDocument properties)
          throws InvalidMetadataException

Parameters:

properties - the json properties object. It must include the following properties:

• type
• uri
• map
• reduce

Optionally it can include the following property:

• query

Note that the dollar prefixed operators in the query must be underscore escaped, e.g. "_$exits"

Example: aggregations: [ { "type":"mapReduce", "uri":"test", "map":"function() { emit(this.name, this.age) }", "reduce":"function(key, values) { return Array.avg(values) }", "query": {"name":{"_$exists":true}} }]

Throws:

InvalidMetadataException

Method Detail

getMap

public String getMap()

Returns:

the map

getReduce

public String getReduce()

Returns:

the reduce

getQuery

public org.bson.BsonValue getQuery()

Returns:

the query

getResolvedQuery

public org.bson.BsonDocument getResolvedQuery(org.bson.BsonDocument aVars)
                                       throws InvalidMetadataException,
                                              QueryVariableNotBoundException

Parameters:

aVars - RequestContext.getAggregationVars()

Returns:

the query with unescaped operators and bound variables

Throws:

InvalidMetadataException

QueryVariableNotBoundException

getResolvedMap

public String getResolvedMap(org.bson.BsonDocument aVars)

Parameters:

aVars - RequestContext.getAggregationVars()

Returns:

the map function with bound aggregation variables

getResolvedReduce

public String getResolvedReduce(org.bson.BsonDocument aVars)

Parameters:

aVars - RequestContext.getAggregationVars()

Returns:

the reduce function with bound aggregation variables